Pressure transmitters are commonly used in industrial processes to measure pressures in various industrial process fluids, such as slurries, liquids, vapors and gases of chemical, pulp, petroleum, gas, pharmaceutical, food and other fluid-type processing plants.
Differential pressure transmitters generally include a pair of process fluid pressure inputs which are operably coupled to a differential pressure sensor (within the differential pressure transmitter) that responds to the difference in pressure between the two inputs. Differential pressure transmitters typically include a pair of isolator diaphragms that are positioned in the process fluid inlets and isolate the differential pressure sensor from the harsh fluids being sensed. Pressure is transferred from the process fluid to the differential pressure sensor through a substantially incompressible fill fluid carried in a passageway extending from each isolator diaphragm to the differential pressure sensor.
Several common types of process fluid flow measurement devices (i.e., flowmeters) employ a variety of different technologies (venturi, orifice plate, v-cone, etc.) that utilize differential pressure measurements as a core technology in order to enable the flow measurement. The differential pressure measurements are typically in the range of 0-75 psi.
Flowmeters relying on differential pressure are common in the oil and gas industry. As off-shore oil drilling employs such differential pressure measurements for measuring pressure in deeper waters, the average pressure of oil coming out of the well increases. Currently, oil and gas companies are attempting to develop technologies that will work with a maximum pressure of 20,000 psi. Accurately measuring a differential pressure in the range of 0-75 psi between two sources with an average pressure that can be as high as 20,000 psi is very challenging.
Providing a pressure sensor module adapted for high working pressure applications, such as sub-sea environments, without requiring extensive modification or expense will facilitate the more widespread adaption and utilization of differential pressure sensors in such applications and will improve the processes that employ such technology.